# Copyright 2018 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""An example DAG demonstrating use of variables and how to test it."""

import datetime

from airflow import models
from airflow.operators import bash
from airflow.operators import dummy


yesterday = datetime.datetime.now() - datetime.timedelta(days=1)

default_dag_args = {
    'start_date': yesterday,
}

with models.DAG(
        'composer_sample_variables',
        schedule_interval=datetime.timedelta(days=1),
        default_args=default_dag_args) as dag:
    start = dummy.DummyOperator(task_id='start')
    end = dummy.DummyOperator(task_id='end')
    variable_example = bash.BashOperator(
        task_id='variable_example',
        bash_command='echo project_id=' + models.Variable.get('gcp_project'))
    start >> variable_example >> end
